High voltage direct current transmission converter valve test equipment is used to test converter valve under worst operation condition and fault condition. It is a necessary equipment to accomplish converter valve type test. Converter valve is made up of many thyristor valves series or parallel connection. Now the voltage and current tolerance of converter valve are increasing with the increasing tolerance of thyristor valve. It requires much higher to the operation test equipment. To reduce the capacity of equipment, the international community usually adopts synthesis method to carry out operation test. Its basic principle is: the high voltage, high direct current, current surge and voltage surge are imposed on converter valve sample one by one through high voltage small current circuit, direct small voltage high current circuit, current surge circuit and impulse circuit respectively and by interval.
The main circuit of synthesis type converter valve operation test equipment includes converter valve sample, auxiliary valve, isolator, breaker, water cooling system, reactor, capacitor and transducer etc. To carry out each operation tests and minimize the damage of the abnormal condition, one complete function and good performance control and protection system. Chinese patent CN100392419C presented a synthesis all condition test equipment control and protection system and method. The system included top control and protect system, synthesis all condition test equipment measure system, electric charging circuit control and protection system, first water cooling device control and protection system, synthesis all condition test circuit control and protection system, second water cooling device control and protection system, small voltage high current control and protection, console and oscillograph; it included five independent subsystem, designed eight protection against different faults and nine priority according to fault severity condition. But this present invention is different from that invention in substance.
(1) Different usage. The invention CN100392419C control and protection system is used to control small voltage charging circuit, synthesis all condition test circuit and small voltage high current source, in fact it is designed for the flexible alternating current transmission thyristor valve operation test. But this present invention said control and protection system is used to control high voltage power system, high direct current power system, high voltage circuit, high direct current circuit, current surge circuit and impulse circuit to accomplish IEC60700(GB/T20990) defined all HVDC converter valves whole operation tests.
(2) Different control function. The invention CN100392419C control and protection system trigged test circuit and thyristor valve only according to fixed timing. Once each thyristor valve unlocked, the trigging number and phase are all fixed during each test period. But in this invention trigging time of each converter valve can change at times, even after the converter is unlocked the trigging number and phase can change according to different requirement. This will avoid abnormal faults because of trigging timing.
(3) Different protection function. The invention CN100392419C designed eight protection measures according to different faults, nine propriety according to different severity. This made this system the protection logic complicate and reduced reliability. On base of abnormal condition deep analysis, our invention separates all abnormal condition into three ranks: common abnormal, hazardous abnormal, emergency abnormal. The invention makes different measures separately: decoupling exit strategy, locking exit strategy and continuous trigging exit strategy according to different rank. This simplifies the protection function and system, improves the reliability of system.
(4) Different local controller. The invention CN100392419C third layer control and protection subsystem includes: electricity charging control and protection subsystem, first water cooling equipment control and protection subsystem, synthesis all condition test circuit control and protection subsystem, second water cooling equipment control and protection subsystem and small voltage high current source control and protection subsystem. This present invention said local controller includes: high direct current supply power controller, high voltage supply power controller, current surge circuit controller, impulse circuit controller, thyrisitor water system controller and test equipment water controller because of different function from invention CN100392419C. Except that the protected objects of two water cooling system controller is similar to the patent CN100392419C, our invention are all different from it.
(5) Different level structure. The patent CN100392419C control and protection adopted level structure and separated three levels clearly. Third level control and protection subsystem had not relation with “console” and “oscillograph” clearly. This invention adopts function element elements connection structure; there is no level structure concept. Various local controllers are connected with console directly through “long-distance CAN bus”. This makes operators much faster communicate information with local controller.
(6) Patent CN100392419C had not presented detail methods of top layer control and protection system, synthesis all condition test equipment measure system. This invention provides control and protection detail function distribution and working timing. This point is original.